Uploaded image for project: 'Minecraft: Java Edition'
  1. Minecraft: Java Edition
  2. MC-239880

Some chunks have missing blocks below 0

    XMLWordPrintable

Details

    • Bug
    • Status: Resolved
    • Resolution: Fixed
    • 21w43a, 21w44a, 1.18 Pre-release 1, 1.18 Pre-release 2, 1.18 Pre-release 3, 1.18 Pre-release 4, 1.18 Pre-release 5
    • 1.18 Pre-release 6
    • None
    • Confirmed
    • Datafixer, World generation
    • Important

    Description

      The bug
      I was exploring around with new biome blending and noticed a chunk formation underground, I went to it and it was all air below 0 and converted incorrectly. This is very rare to happen as I seen the other chunks are fine. I checked the logs are there are 3 errors that are all in the same minute, but this happened on my other world without any error in logs.
      UPDATE: The cause of this issue is when caves are generated below old chunks, the chunk contains no bedrock so it won't attempt to place caves below this chunk since after testing around, the chunk must contain at least 1 block of bedrock at Y=0 in the world for it to fill the bottom with caves. The fix would be detecting if the chunk contains an block at Y=0 instead of detecting only Bedrock.

      Steps to reproduce
      1. Load a world from 1.17.1 or below on 1.18 Pre-release 5 (or load Below 0 world bug.zip)
      2. Explore around next to the blended area (If on downloaded world do: /tp -1201 -9 -85)
      3. You can notice missing chunks but It is rare.

      Observed result
      Empty chunks below 0

      Expected behaviour
      Chunks to generate like the other chunks around

      Attachments

        1. 1-17-1-worldbug.png
          1-17-1-worldbug.png
          472 kB
        2. Below 0 world bug.zip
          1.12 MB
        3. bugimage1.png
          bugimage1.png
          1.45 MB
        4. bugimage2.png
          bugimage2.png
          1.42 MB
        5. image-2021-10-27-20-38-59-086.png
          image-2021-10-27-20-38-59-086.png
          1.76 MB
        6. image-2021-10-27-20-43-29-347.png
          image-2021-10-27-20-43-29-347.png
          1.38 MB
        7. image-2021-10-27-20-45-19-271.png
          image-2021-10-27-20-45-19-271.png
          446 kB
        8. screenshot-1.png
          screenshot-1.png
          1.51 MB
        9. screenshot-2.png
          screenshot-2.png
          2.81 MB
        10. screenshot-4.png
          screenshot-4.png
          1.94 MB

        Activity

          People

            panda4994 [Mojang] Panda
            Welcome_234 Welcome 234
            Votes:
            11 Vote for this issue
            Watchers:
            7 Start watching this issue

            Dates

              Created:
              Updated:
              Resolved:
              CHK: